BARNABY Joyce and his estranged wife Natalie went on a seven day trip to Europe together in late June last year, shortly before the Deputy Prime Minister's girlfriend Vikki Campion fell pregnant.

Mr Joyce visited Britain, Belgium, Italy and the Netherlands to map out Australia's trade future in the wake of Brexit in late June, early July, and was accompanied by his wife for the week.

The pair went to London Bridge on June 25 to lay flowers and pay respects to victims of the Borough Market Islamic terror attack, before visiting the local pub together where Mr Joyce enjoyed a beer with staffers and his wife.

Mr Joyce confirmed today Ms Campion was expecting to give birth to their child in mid-April, indicating the couple fell pregnant in mid-July, weeks after the trip with his wife.

Deputy Prime Minister Barnaby Joyce and his wife Natalie (left) paying their respects at London Bridge in late June. Picture: Christopher Chan

Mr Joyce and his wife also attended the Mid Winter Ball in Parliament House together on June 14.

The news comes as The West Australian reports, in total, Mr Joyce spent more than $10,000 on family travel between January and September last year.

More than half of the travel expenditure was claimed from July to September, when Ms Campion was pregnant with their child.

Most of the travel was claimed for flights from Tamworth to Canberra or Sydney.

It's understood none of the claims were for Ms Campion, who the Prime Minister's office said yesterday was not officially considered his partner at the time. She was employed in fellow Nationals MPs offices at the time.

Barnaby Joyce and his wife Natalie arriving at the Federal Parliament Midwinter Ball 2017, at Parliament House in Canberra. Picture Ray Strange

JOYCE 'DEEPLY SORRY'

In a statement today, Mr Joyce denied he and Ms Campion were in a relationship while she worked in his office.

"I deeply regret the failure of my 24-year marriage, the tremendous hurt caused to Natalie and our four daughters and the unwanted public intrusion into what is an intensely private matter for all of us," he said in the statement.

"My marriage was under pressure for some time. Natalie and I tried to make it work again in April last year but it subsequently came to an end.

"This and similar nonsense has been retailed in the past by embittered political opponents."

Questions were raised yesterday over whether ministerial standards were breached when Ms Campion, who will give birth to his child in April, was appointed to roles in the offices of Resource Minister Matthew Canavan and Nationals MP Damian Drum last year.

Today, Mr Joyce denied there was any breach over the roles, while confirming he and Ms Campion were having a child together in mid-April.

"In 2016 Vikki worked on the election campaign and in August came to work on my staff.

"A friendship subsequently developed and that became, over time, more.

"In April last year she went to work for a senior colleague, Mr Canavan.

"She was well qualified for the role, was an existing and obviously capable staff member and the change was within the existing Nationals staff arrangement.

"I did not discuss these matters with the Prime Minister or his office as Vikki was not my partner, so they were dealt with in the usual course of staff deployments within the Party.

"When Mr Canavan stood down over the citizenship issue she went to work for another MP and subsequently left the Nationals staff following the most recent reshuffle."

In a plea for privacy, Mr Joyce, who also made a brief statement at Parliament this morning, said: "This has been a searing personal experience for Natalie, our daughters and for Vikki - criticise me if you wish but please have some regard for them."

Mr Joyce's estranged wife Natalie's statement last week seemingly refutes Mr Joyce's claim that he was not in a relationship with Ms Campion when she worked for Senator Canavan.

"I understand that this affair has been going on for many months and started when she was a paid employee," Mrs Joyce said in a statement when the affair was first reported.

She said she was "deeply saddened" by the reports her husband had been having an affair with Ms Campion and that they were now expecting a child together.

It’s been a horror couple of weeks for the Deputy PM. Picture: AAP/Lukas Koch

JOYCE WON'T RESIGN

Earlier today, Mr Joyce told ABC he would not step down as leader of the Nationals party, amid calls for him to resign following the affair scandal with his former staffer.

The incident reportedly happened at a Rural Women's Agricultural Awards in Canberra in after a woman spoke to the Deputy Prime Minister about his interaction with another woman at the event.

She told The Daily Telegraph last night: "I went over to the bar and he was very, very drunk and nearly falling over. I said 'Barnaby, I think you should go home. You're very drunk. He leant over and he pinched my bottom."

Finance Minister Mathias Cormann told reporters in Canberra today the government backed Mr Joyce "as a friend and colleague", while confirming the Nationals leader would make the statement today.

"Barnaby is big and ugly enough to explain himself," he said.

"I understand he's going to make a statement later today. It will be a matter for others to judge."

LIBERAL PARTY ANGER

Angry Liberal MPs have spoken out about their frustration over the fallout of the affair, calling on Mr Joyce to "resolve" the issue.

"Barnaby was a favoured son of Queensland," Senator Macdonald told reporters in Canberra this morning.

"He's done a lot of good things over the years. This is something that he has to resolve.

"I know he would be concerned, as I am, that this issue like those same-sex marriage and citizenship issues, which are not really the purview of this Parliament, but they do detract from the government's focus and take oxygen out of getting the message across to Australians just what a great job Malcolm Turnbull and this government is doing."

Liberal Senator Ian Macdonald has his views on the scandal. Picture: AAP

One Liberal MP told The Herald Sun anonymously yesterday that Mr Joyce "has to go" before he gets "blown out of the water".

Another compared the scandal to the Bronwyn Bishop "Choppergate" incident, telling the publication that it was "sucking the oxygen" out of the government.

The MP said the "worst outcome" would be having Mr Joyce take over as Acting Prime Minister when Mr Turnbull travelled to the United States next week to meet President Donald Trump.

Meanwhile, former Nationals leader John ­Anderson also called on Mr Joyce to take "direct responsibility" for the damage the scandal was doing to the government.

Mr Anderson, who was Deputy Prime Minister in the Howard Government, has told The Australian that the National Party and its leader needed to resolve the issue.

"The buck stops with the leader of the National Party and National senators and MPs," Mr Anderson told the publication. He said the situation would "end even more messily" if it was not resolved.

Deputy Prime Minister Barnaby Joyce has been under fire since the scandal broke. Picture: AAP/Mick Tsikas

JOYCE'S JOB 'INCREASINGLY UNTENABLE'

The Opposition is also stepping up pressure on Mr Joyce to resign as it claims the government's story is "unravelling".

"Any incident in which something has happened particularly to a woman that's making her feel uncomfortable is serious," he said.

Mr Bowen also said the Prime Minister's office claim that there was no breach of ministerial standards regarding Ms Campion's appointment to two roles in senior Nationals MP's offices because Ms Campion was not considered Mr Joyce's "partner" at the time was laughable.

He questioned the truth of the claim by a spokesman for the Prime Minister that Mr Turnbull did not know about the affair when Ms Campion was appointed to the roles.

Mr Bowen said the claim appeared to be refuted by reports today that Mr Joyce told Mr Turnbull in August that his affair with Ms Campion was over.